In the discussion of the background that follows, reference is made to certain structures and/or methods. However, the following references should not be construed as an admission that these structures and/or methods constitute prior art. Applicant expressly reserves the right to demonstrate that such structures and/or methods do not qualify as prior art.
Cutting tool assemblies used to cut hard surfaces, such as rock and asphalt, typically include a rotating wheel or drum with a plurality of cutting tools or tool picks mounted around circumference of the wheel or drum. Each tool pick is part of a tool pick assembly that is rotatably mounted within a cylindrical bore of a block, the block being mounted to the rotating drum. Because the material cut by such tool picks is abrasive, the tool picks become worn quickly, and frequently need to be replaced, sometimes on a daily basis. Therefore, replacement of such tool picks must be relatively easy to accomplish.
A tool pick assembly typically includes a tool pick, a sleeve retainer, and a washer. Each tool pick typically includes a tool body, a frontward projecting tapered cutting tip extending outwardly from one end of the tool body and a rearward projecting shank extending outwardly from an opposite end of the tool body. Disposed between the tool body and the shank is a raised shoulder having a diameter larger than the shank but smaller than an adjacent portion of the tool body. The sleeve retainer is disposed about the shank to retain the tool pick within the bore of the block or within a sleeve as disclosed in U.S. Pat. No. 5,725,283, which is incorporated by reference herein in its entirety. The washer may be used to circumferentially compress the sleeve retainer to aid in insertion of the tool pick assembly into the bore in the block. When assembled, the raised shoulder portion of the tool pick is disposed adjacent to the washer, which in turn is adjacent to the block, and the cutting tip is exposed for cutting. In use, the tool pick rotates freely within the sleeve retainer so that the cutting tip wears evenly.
At least two differently sized tool pick assemblies are commonly used in the industry, a first size being defined by a 19.9 mm diameter block bore (nominally referred to as “19 mm”) and a second sized being defined by a 22.5 mm diameter block bore (nominally referred to as “22 mm”). Other sizes may also be defined by other bore diameters. As a result, in order to be able to replace tool picks as they wear out, it may be necessary to keep a stock of two or more differently sized tool pick assemblies, each tool pick assembly including a took pick, a sleeve retainer, and a washer. Similarly, it is necessary for a manufacturer of tool picks to manufacture two or more differently sized tool picks, or at least tool picks having two or more differently sized shanks, to be able to fulfill the needs of the differently sized block bores in the cutting tool assemblies out in the field.
Accordingly, there is a need in the art for an adaptive sleeve retainer to enable a tool pick sized to be received in a first bore diameter to be used in a second bore diameter, wherein the second bore diameter is smaller than the first bore diameter, without compromising the stability of the tool pick supported in the bore and without substantially changing the push out force required to remove the tool pick from the bore.